1. Field of the Invention
The present invention relates to a substrate having fine lines, and a method for manufacturing the same. Particularly, the invention relates to a configuration in which the fine lines are wires provided on the substrate, and a configuration in which a technique for providing the fine lines are applied to an electron-source substrate and an image forming apparatus.
2. Description of the Related Art
FIG. 14A is a plan view illustrating a surface-conduction-type electron emitting device. FIG. 14B is a cross-sectional view taken along line B–B′ shown in FIG. 14A. In FIGS. 14A and 14B, there are shown an insulating substrate 2, a conductive film 15, electrodes 11 and 12, and an electron emitting portion 16.
FIG. 15 is a schematic diagram illustrating the configuration of an image display apparatus which uses electron emitting devices 100, each such as the one shown in FIGS. 14A and 14B. In FIG. 15, there are shown a substrate 151, an external frame 152, and a faceplate 156 having an image forming member 154 disposed thereon.
An envelope (air-tight container) 157 for maintaining the inside of the image display apparatus in a vacuum by sealing respective connecting portions between corresponding ones of the external frame 152, the substrate 151 and the faceplate 153 using a bonding material (not shown), such as a low-melting-point glass frit or the like, is provided.
A substrate 158 is fixed on the substrate 151. The electron emitting devices 100 whose number equals N×M (N and M are positive integers equal to or more than 2, appropriately selected in accordance with the number of pixels for displaying an image) are formed by being arranged on the substrate 158. Each of the electron emitting devices 100 is connected to corresponding ones of wires 159 and 160, each made of a conductive film.
In FIG. 15, M column-direction wires 159 and N row-direction wires 160 (also called “matrix wires”) are provided. Insulating layers (not shown) are provided at intersections of the row-direction wires 160 and the column-direction wires 159, so that the row-direction wires 160 are insulated from the column-direction wires.
In order to form the above-described image display apparatus, it is necessary to form and arrange a large number of row-direction wires 160 and column-direction wires 159.
In order to form and arrange a large number of thick row-direction wires 160 and column-direction wires 159, for example, Japanese Patent Application Laid-Open (Kokai) No. 8-34110 (1996) discloses a method of using a printing technique which is relatively inexpensive, does not require a vacuum apparatus and the like, and can deal with a large area.
In addition to the above-described surface-conduction-type electron emitting devices, for example, spindt-type electron emitting devices, each having a cone-shaped electron emitting portion, and MIM(metal-insulator-metal)-type electron emitting devices have been known as the electron emitting devices. By being combined with a phosphor emitting light by electrons emitted from an electron emitting device, the electron emitting device can be used as an image display device. In addition to the above-described electron emitting devices, for example, EL (electroluminescent) devices have been known as image display devices. A configuration in which an image is displayed by using very small integrated mirrors as image display devices and controlling reflection of light by the very small mirrors has also been known. A configuration in which an image is displayed using liquid-crystal devices as image display devices has also been practically used widely.
Japanese Utility-Model Application Laid-Open (Kokai) No. 5-38874 (1993) discloses another background technique. This application discloses a technique in which in order to connect two conductive films facing each other, resistive films are superposed on respective end portions of the two conductive films. Particularly, in order to prevent growth of cracks in each of the resistive films at a step portion of superposition into a single large crack, the end portion of the conductive film is formed with a crooked line comprising lines or curves, having a saw-tooth shape, a comb-like shape, a wavy shape or the like.